Step 5) Add a Display Rule under your forms Visibility settings to make the form only show on Mobile devices

Here’s what AppSumo’s final visibility settings look like (you can choose to not show your popup on specific pages like AppSumo, or just have it run across your whole site).

This popup works so well because you are taking your highest-converting popup on Desktop and creating a new button layout roughly lined up right under the user’s thumb to make it easier for your website visitors to opt in while browsing on mobile.